You can see the difference between how this product acts on the live site vs staging: on the live site I have stripe gateway disabled, and the product variants work correctly (easiest to see when the product page updates pricing).
On the staging site I enabled stripe gateway so it’s stuck on the default variant.
https://www.yaelharrisresnick.com/product/earth-air-fire-water-set-giclee-and-poster-print-copy/
https://staging.yaelharrisresnick.com/product/earth-air-fire-water-set-giclee-and-poster-print-copy/